Variable delivery pump



Jan.'18, 1949. D. J. MUNROE ETAL 2,459,383

VARIABLE DEL'IVERY PUMP Filed July 23, 1945 I '3 Shee'ts-Sheet 1 N "-12. I I I VI & I Jzdezzzvrd' w Joan cmqzu Jadz'd J ifwzrae Jan. 18, 1949. D. J. MUNROE ETAL 8 VARIABLE nELIvEgY PUMP Filed July 23, 1,945 3 sheets she et 2 (3 '0 |n HUM I 9 B W MM Jan. 18,1949. MUNRQE ETAL 2,459,388

VARIABLE DELIIERY PUMP Filed July 23, 1945 3 Sheets-Sheet 3" w T- i & a

Patented Jan. 18, 1949 2,459,388 VARIABLE DELIVERY PUMP David J. Munroe and John C. McAlvay, Racine,

Wis., assignors to Webster Electric Racine, '15.,

Company,

a corporation oi Delaware Application July 23, 1945, Serial No. 608,619 Claims. (Cl. 103-41) The present invention relates to variable delivery pumps, and is particularly concerned with pumps of the reciprocating type.

One of the objects of the present invention is the provision of an improved variable delivery pump, the delivery or output of which may be varied continuously or by infinitely small increments from full discharge to zero discharge or no delivery.

Another object of the invention is the provision of a pump of the class described, the amount of delivery of which may be varied while the pump is operating or while the pump is still, with such accuracy that the pump may be made to deliver a full stream or it may be made to deliver liquids drop by drop so that a measured amount of input may be delivered responsive to the turning of a control shaft.

Another object of the invention is the provision of an improved variable delivery pump of the class described which is simple in construction, the parts of which are automatically lubricated and the parts of which are adapted to be economically constructed and used for a long period of time without necessity for repair or replacement.

Another object of the invention is the provision of a variable delivery pump of the class described in which the delivery of the pump may be varied by the movement of certain control valves which are adapted simultaneously to move into a position in which a predetermined amount of the output is bypassed back to the inlet of the pump and the output of the pump is automatically cut off by the same effective amount as the bypass, the cutoff of the output serving to force the fluid being pumped into the bypass channels so as to make the variable delivery positive and accurate.

Other objects and advantages of the invention will be apparent from the following-description and the accompanying drawings, in which similar characters of reference indicateslmilar parts throughout the several views.

Referring to the drawings, of which there are three sheets,

Fig. 1 is a plan view of the pump with the cover plate removed, showing the parts in the position which they assume when the valves are adjusted for full delivery, but the inlet control ports are momentarily out-of registry, but are approaching the position of registry for intake into the pumping space below the shuttle block or piston;

Fig. :2 is a view similar to Fig. l, with the variable delivery controlling valves in the same position, but the trunnion block which controls the to the lower side which a lesser amount or fluid is deportion of the fluid being pumped being bypassed back to the inlet port;

Fig. 4 is a view similar to Fig. 3 in that the variable delivery valves are in the same position, but the trunnion block has passed the position of Fig. 2 and is about to be moved out of'registry with the inlet ports to the lower side of the shuttle block or piston, as this piston has almost reached the upper limit of its stroke, when its motion will be reversed;

Fig. 5 is a vertical sectional view taken on the plane of the line 5--5 of Fig. 4, looking in the direction of the arrows, showing the body member of the pump, the cover plate, and the intermediate pump housing plate;

Fig. 6 is a transverse'sectional view, taken on the plane of the line 6-6 of Fig; 3, looking in the the pump and the other associated parts at this plane;

Fig. 7 is a view in perspective of the shuttle block or piston member of the pump;

Fig. 8 is a view in perspective of the trunnion block or main valve member of the pump; and

Fig. 9 is a view in perspective of one of the variable delivery valve members of the pump.

Referring tov Figl 5, the present pump preferably includes a supporting body member H, a member l2, and an intermediate housing plate i3, all of which may be secured together by suitable screw bolts M, which pass through the members l2 and I3 and are threaded into the body I l.

The mechanism of the pump is enclosed in the chamber or chambers provided inside the housing plate It, which are closed on each side by the cover plate H2 or body member II. This mechanism preferably includes a trunnion block IS, a shuttle block or piston l6, 2. pair of variable delivery valve members ll, 18, a pivoted lever l9, and shaft 28.

The trunnion block l5, shuttle block l6, and valves ill and it are of the same thickness, but of slightly lesser thickness than the housing plate ill, so that when the trunnion block l5, shuttle block it, and valves ll are assembled between the body member H and cover plate lithere is that which is provided by the fluid being.

pumped; but when the pump is beingnised for pumping liquids or fluids having no lubricating qualities, suitable arrangements for the lubrication of the pump should be included.

. shaped aperture inFigJl.

The body member II is preferably provided with a substantially planeface 2| for engaging a similar surface 22, which is located on those parts of the housing plate ii that are not otherwise apertured and which in particular extend all theway around the border of the housinB plate I3, as seen in Figs. 1 to 4.

The body member -II is also provided with a cylindrical bore 23, serving as a bearing for the shaft 24, which has a cylindrical portion of sumcient length to extend from end to end of the I bore 23 and is provided at its inner end with an eccentrically located cylindrical trunnion 25 projecting into the centrally located part of the chamber in the housing plate i8.

Adjacent its lower end in Fig. 5, the. body member II is also provided with a second through bore 26, serving as a bearing for the variable delivery valve shaft 21, which extends through the bore 26 into the pump chamber, where it passes through a registering bore 28 in the housing plate l3 and terminates in a slot 29 with a noncircular end portion 80, which carries a valve actuating lever iii.

The cover plate i2 may consist of a flat metal plate having a pair of plane surfaces, the innermost of which, 32, forms one of the walls of the pump chamber inside the housing plate I8.

4 of one upper leg. and III the plane ,wall definin! the inside of the other or right upper leg of the H shaped aperture. Ii and 52, respectively, indicate'the inner walls of the lower legs of the H Thus it will be'observed that the aperture in the housing plate [3 is substantially the same shape as a capital H, but the middle bar portion of the aperture is relatively wide, extending from wall 41 to wall 48.

- The two legs of this H shaped aperture are partially filled by the variable delivery valve members H, I! (Fig. l), which are of substantially rectangular shape in cross-section, as seen in Fig. 9, and of suiflcient size to slide in the rectangular recess which is located at the right and left sides of the housing plate 13.-

-The exact shape of. these variable delivery valve members will be further described in detail. The rectangular middle portion of the H shaped aperture between the walls 41 and 48 and between the variable delivery valve members I! and I8 is occupied in part by the shuttle member or piston i8, which is also substantially rectangular in plan and elevation and of such size that it is adapted to slide in engagement with the valve In addition to the foregoing openings, the

body member Ii is preferably of sufllcient thickness so that it may be provided with an inlet bore 33 and an outlet bore 34 extending into the body member Ii from its opposite edges; and these bores are suitably threaded in their outer ends to receive pipe fittings for connection to pipe for carrying the fluid to and from the pump. The inlet bore 33 communicates with the inner face 2| of the body member Ii through a drilled aperture 85, which is at substantially right angles to the face and which is seen in Figs. 1 to 4 and Fig. 6.

The outlet 34 communicates with the face 2i of the body member II by means of a pair of drilled bores 36 and 31, each of which communicates with an elongated slot 38, 39, respectively, located in the face 21 of the body member II.

The housing plate 13 is provided with the ground faces 22 and 40 located adjacent its edge for engagement with the complementary surfaces on the body member II and cover i2. This body plate is pierced by means of a substantially H shaped aperture, the borders of which are indicated as follows in Fig. 1. 4| indicates the left wall of the aperture and 42 the right wall. The ends of two upper legs of the H shaped aperture are indicated by 43 and 44, while the ends of the two lower legs of the H shaped aperture are indicated by 45 and 46.

What might be called the middle bar of the 'H shaped aperture is bordered at the top by the plane wall 41 and at the bottom by the plane wall 48. 49 indicates the wall defining the inside members i1 and IS, the body member II, and cover i2, from a point adjacent the lower wall 48 to a pointadlacent the upper wall 41.

The open space above the piston or shuttle member i8 is indicated by 53, and the open space below the shuttle member is indicated by the numeral 54.

The shuttle member i8 is thus adapted to act like a piston, but it also is provided with a centrally located through aperture, indicated by the numeral 55, and bounded on the two sides by the walls 56, 51 and above and below by walls ll, I9, each of these walls being a plane surface. I

The rectangular aperture 58 is adapted to re ceive the trunnion block I! for sliding movement.

The width of this trunnion block I! is less than the distance between the walls 58, 51 in the aperture 55 of shuttle block I8, thus permitting a reciprocating movement in a horizontal direction, as indicated by the open spaces 82, 83 on each side of the trunnion block IS.

The plane side surfaces of this trunnion block are indicated by 64 and 65. The trunnion block l5 has a through cylindrical bore 66 for engaging the eccentric trunnion 25, which, however, is shorter than the thickness of the trunnion block I6 so as to leave the transverse groove 61 on the face 68 of the trunnion block l5 open.

The groove 81 connects the spaces 62 and 68 on either side of the trunnion block it in the aperture 55 so that the trunnion block effects no pumping action by virtue of its own movement in the aperture 55.

The two diagonally opposite corners at the upper right and lower left (Fig. 1) of trunnion block iii are notched, preferably with substantially rectangular notches 69 and 10, to provide ports that communicate with ports II and 12 in the shuttle block or piston i8.

It will be noted that the notches 89 and III are in registry with the slots Ii and 12 at proper times because both are located in the upper faces end surfaces Ill-and 6| of the trunnion block II and shuttle block ll, respectively.

The slots II and 12 provide communication between the inner aperture II in the shuttle block l6 and the spaces II and SI at either end of this piston l5.

The trunnion block I! is also provided in the with rectangular slots 13 and M, which extend all the way through from the front face to the back face of the block l5, as shown in Fig. 8.

These slots 78 and 74 are located to communicate at a proper time with slots 39 and 38 in the body member and with the passageways l and it in the shuttle block l6. Passageways l5 and it each extend outwardly from the central aperture it in. the shuttle block l6 and laterally in indicated at ll, it, then backwar'dly at Ill and as and outwardly in vl'de ports ill and assageways ll. at, and it, it, Bil and hi? are in. the form of rectangular slots located in the face of the shuttle block but the port portions iii, 8d are in the form of rectangular slots which extend from the front to the of the shuttle block iii, as seeen in Fig. i

In addition to the foregoing, the shuttle block i l is provided in its upper right corner on its rear face with a downwardly extending slot til, which extends laterally, forming a port'% in the right side till of the shuttle bioclt it. In the lower right corner the rear face of the shuttle block it is formed. with a rectangular slot to extending up wardiy and terminating in a port ill in the left side llil elf-the shuttle bloclr iii.

The variable delivery valve members ll and iii are similar in construction, but certain slots are reversed in position because of the location of these member on the left and right hand side. The valves El and it are slotted on the upper surface transversely at Eli and 9d, transversely of each of these members, with a rectangular slot. These slots are located. one at one end of the pump and the other at the other end. Thus the slot lid is adapted to communicate with the space below the piston, and the slot fill is adapted to communicate with the space 53 above the piston, when the valve members El and it are suitably adjusted.

The valve members it and it are substantially rectangular in shape; but are each slotted at their faces at the outer corner to provide a rectangular cut-out t t and 92 extending the full length of each valve member ii" and it.

Each valve member ll and id is grooved on its lower surface with transversely and inwardly extending grooves as, a l, iltl, at. These grooves 5% are joined by a longitudinally extending groove ill, and the grooves 95, are joined by a longitudinally extending groove When the valve members ll and it are suitably assembled with the other parts of the mechanism, the grooves to 96 form ports, while the grooves form. passageways communieating with these ports. Each valve member ill and it has its lower and (Fig. 1) formed with a rectangular cut-out as provided with an out wardly projecting cylindrical pin illil.

The pins tilt are adapted to be engaged by the forked ends of the lever which is provided with a suitable slot tilt and spaced legs m2, 563. The pump hot member it is grooved at each end to fern. tangular slots iil i, fllih, which iii, as shown in Fig. 7;'

it'll direction in Fig. 1,

extend from side to side and provide communication between the open spaces at the valve members I1 and I9.

The lower one of these slots 05 in Fig. 1 also provides room for the pivoted lever IS. The pump housing member I3 is also slotted in its left wall in Fig. 1 through its entire thickness to form the slot I06. which communicates with a drilled passageway I01 extending from the face of the body member ll into the intake port 33 in order that excess fluid may be by-passed back to the inlet when the pump is not on full delivery.

The operation of the pump is as follows: In Figs. 1 and 2 the variable delivery valves ii and It are set for full delivery. When theshalt it is rotated, as for example in a counterclockwise the eccentric trunnion 2% will cause the trunnion block iii to be reclprocated from left to right and upward and downward in a circle.

The size of the aperture 55 in the shuttle blocl; it (Fig. '7) is such that the lateral motion of the trunnion block ill is trunnion bloclr slides in this aperture tit. No pumping takes place between the spaces iii and $3 at either end or" thetrunnion bloclr it because the open groove permits the fluid to pass freely from left to right, or vice versa, in these places.

As the eccentric trunnion fill moves the trunnion block it] up or down in Fig. i, this trunnion block. carries with it the shuttle block or piston iii, which. reciprocates in the space between the walls iii and dd, slidably engaging the sides of the valve members ii and it? and causing the spaces iii; and to alternately Vary in size or volume.

It is this shuttle blocls it which accomplishes the pwnping action.

In l. the space iii? is about and the space till is about to be diminished in size, as the eccentric trunnion 25 is on the lower dead center. As the shaft revolves, the cut-out ill comes into communication with passageway it, which communicates with lower space The cut-out ill communicates with the space ti! and drilled aperture 355 to the inlet 33 Thus, as the space is enlarged by upward movement of the shuttle blocl; or piston fluid is drawn in through the inlet so, passageway 35, space til, cut-out Hi, and passage it, to the space 5d below the piston.

The movement of the shuttle block it upward from the position of 1 will cause theport til to again register with port 96 and port at to register with port When this happens, the fluid in the space above the piston will pass down the passage port at, to port 933, passage ill, port port passage lit, passage it, passage it, slot it, slot ilfl, passage $55, to out let 3%.

This action continues until the shuttle" blocl: ill has reached its upper limit of motion and the trunnion it is at the upper position opposite to that of Fig.

In Fig. 2 the parts rave moved into the position of registry just described, and fluid is being drawn. in through the inlet port 33 into the lower.

space and is being discharged from the upper space 53 out of the outlet port as the trunnion reaches its uppermost position opposite to that of driven out of the ups space below a and the lower pit-ton entirely filled with ends of the I permitted, while the to be enlarged,

asaasee Then a reversal in the motion oi the piston takes place, and shuttle block it moves-downward. During this motion the cut-out 89 communicates with passageway Ii, which communicates with space 83. passage 61, space 82,'passageway II, and inlet 38.

Then on the downward motion of the piston or shuttle block l6, fluid is drawn in through the passages just described, to fill the space 63.

In the meantime fiuid is being forced out of the lower space 56 through the following passages: port 81, which hasbeen aboveport 95, comes down into registry with port 95, port 8| comes into registry with port 88. Also slot 13 in trunnion block it comes into registry with port iii.

Then, as the shuttle block it passes downward, fluid in the lower space 54, which is now completely full, passes'out oi the passage 86, port 81, port 95, passage 98, port st, passage ti, passage l8, passage Ti, passage i5, slot 73, and. passage 39, passage 31, to outlet at. i

This is the operation of the pump livery.

Referring now to Fig. 3, the variable delivery valve actuating member is has been moved to an intermediate position, somewhere between full delivery and no delivery. This moves the valve member ii down and valve member is up from the positions of Fig. 1. The port as is thus moved down closer to the space 65, and the port so has been moved upward, closer to the space 53.

During full delivery, as shown in Figs. 3 and 4,

for full dethese ports as and 96 are inoperative because they are located beyond the range of operation oi the shuttle block it, so that they never become uncovered.

specific iorm 'or shape or location of the parts.

In the valve position of Fig. 3, however, as the shuttle block it moves upward, it soon uncovers the port as. During that portion of the stroke when the ports 89 and 90 are covered, there will still be full delivery, but during that portion of the stroke when the.ports 89 or 90 are uncovered, fluid, which is driven from the spaces 52 or 53 will be by-pass fuel back to the inlet port 33, as follows:

Suppose, for example, the shuttle member i5 is moving upward in Fig. 3 until port 90 is covered by shuttle block iii, liquid will pass through port 90 into the passage 92, thence longitudinally'to either end of the valve member is, transversely through slots I04, I05, and past the end of the valve member [1, into passageway ill', thence through slot Hi6 and bore I01 into the inlet 33. This by-passing action might take place irrespective of any positive cutoff of delivery, as there is a suction applied to the fluid passing out of the space 53 to the inlet, and thence into space 54 during this operation.

However, delivery at this time may also be postively cut off by the action of valves i1 and i8 because ports 93' and 94, for example, have also been moved upward in Fig. 3 from the position of Fig. 1, and port 93 does not come into registry with port 84 nor port 94 into registry with port 82 until this by-passing action has finished and the shuttle block i6 has moved up to cut off the port 90.

As registry between ports 96 and 94 with ports 84 and 82, respectively, is also required for delivery, it will be seen that delivery is also positively cut of! While the by-passing action is taking place.

Thus theadjustment of the valve members For example, it may be-that in some embodiments of the invention the trunnion block ll may be made shorter in a lateral direction in Fig. 1, thus eliminating the necessity for the cut-outs I! and 10 at the corners thereof.

Also, it may be possible in other embodiments to elongate the slots 38 and 39 and to make the trunnion block iii shorter in a vertical direction in Fig. 1 to eliminate the necessity for slots 13 and 14. Various other similar changes may be obvious to one skilled in the art.

It will thus be observed that we have invented an improved reciprocating pump, the delivery of which is adapted to be varied continuously without steps from maximum to zero so that this pump may be used for measuring the output of lubricant or liquid fuel, or it may be used to pump gases, suitable provision being made for its lubrication.

When pumping the relatively noncompressible liquids, its delivery may be very accurately predetermined'and measured so that such pumps may be used on oil burners, for example, to predetermine the amount at heat by providing a measured amount oi. fuel, or the amount oi, lubricant provided to the bearing suriaces of a machine may be accurately measured and supplied by a pump of this character. 7

While we have illustrated a preferred embodiment of our invention, many modifications may be made without departing from the spirit of the invention, and we do not wish to be limited to the precise details of construction set forth, but desire to avail ourselves 01 all changes within the scope oi the appended claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States, is:

1. In a fluid pump of the reciprocating type, the combination of a supporting body provided with a rotating shaft having an eccentric trunnion extending into a pump cavity in said body, with a reciprocating member engaged by said trunnion and adapted to be reciprocated in said cavity by said trunnion, said body beingiormed with inlet and outlet ports and said reciprocating member being formed with passageways and ports adapted to be alternatively connected to provide communication between the inlet and a pumping space and between the outlet and-said pumping space, and adjustable valve means interposed between the outlet port and passageways extending from the pumping space to the outlet port, whereby a predetermined amount of the output may be diverted from the output to effect a predetermined measured discharge of said pump, said body being provided with passageways for conducting the fiuid which is diverted from said outlet port back to the inlet of said pump.

2. In a reciprocating pump, the combination of a pump housing provided with a pump chamber defined in part by a pair of opposed parallel plane surfaces,-said housing being provided with a bearing for a shaft, said shaft having anecthe space between the said trunnion and ot a thickness adapted to be slidably received between said parallel walls, said trunnion being moved in a predetermined orbit by said trunnion, a piston block'having an aperture provided with opposed plane surfaces for slida-bly engaging said trunnion block, said piston block being of a thickness having a sliding fit between the opposed surfaces of said chamber, and said piston block being reciprocated in said chamber by said trunnion block, a pair of valve members, one mounted on each side of said piston block in said chamber, said valve members being movabiy mounted for movement in the same direction as said piston block, said housing being provided with inlet and outlet ports and with passages and ports communicating with end of said housing and one endoi said piston block, whereby the rotation oi said shaft reciprocating said piston bloclr automatically opens valves to the inlet port as said space increases in volume and closes said ports and opens other ports leading to the outlet port from said space when the piston block moves in the opposite direction. i ii. In a fluid pump of the reciprocating type, the combination of a supporting body provided with a rotating shaft having an eccentric trunnion extending into a pump cavity in said body, with a reciprocating member engaged by said trunnion and adapted to be reciprocated in said cavity by said trunnion, said body being formed with inlet and outlet ports and said reciprocating member being formed with passageways and ports adapted to be alternatively connected to provide communication between the inlet and a pumping space and between the outlet and said pumping space, and adjustable valve means interposed between the outlet port and passageways extending from the pumping space to the outlet port, whereby a predetermined amount oi the output may be diverted from the output to effect a predetermined measured discharge oi said pump, said body being provided with pumping spaces at both ends of said reciprocating member, and said valve means controlling passageways from both oi. said spaces to the outlet.

In a fluid pump of the reciprocating type, the combination of a supporting body provided with a rotating shaft having an eccentric trunnion extending into a pump cavity in said body, with a reciprocating member engaged by said trunnion and cavity by said trunnion, said body being formed with inlet and outlet ports and said reciprocating member being formed with passageways and ports adapted to be alternatively connected to provide communication between the inlet and a pumping space and between the outlet and said pumping space, and adjustable valve means interposed between the outlet port and passageways extending from the pumping space to the outlet port, whereby a predetermined amount of the output may be diverted from the output to effect a predetermined measured discharge of said pump, the said body being formed with a substantially rectangular pump chamber and said trunnion being connected to said reciprocating member through the intermediary oi a trunnion block adapted to reciprocate in a transverse direction in said chamber.

5. In a fluid pump of the reciprocating type, the

' combination of a supporting body provided with a rotating shaft having an eccentric trunnion eitending into a pump cavity in said body, with. a reciprocating member engaged by said trunnion said trunnion, said and adapted to adapted to be reciprocated in said block, said housing being 1 and adapted to be reciprocated in said cavity by body being formed with inlet and outlet ports and said reciprocating member being formed with passageways and ports adapted to be alternatively connected to provide communication between the inlet and a pumping a space and between the outlet and said pumping space, and adjustable valve means interposed bemay be diverted determined measured discharge of said pump, the

formed with asubstantially chamber and said trunnion being connected to said reciprocating member through the intermediary of a trunnion bloclt adapted to reciprocate in a transverse, direction in said chamber, said trunnion block being provided with passage means for controlling the alternative discharge of fluid from the spaces at the opposite ends of said, reciprocating member.

6. In a fluid pump of the combination of a supporting body provided with a rotating shaft having an eccentric trunnion err-- tending into a pump cavity in said body, with rt reciprocating member engaged by said trunnion be reciprocated in said cavity by said trunnion, said body being formed with inlet and outlet ports and said reciprocating member being formed with passageways and ports adapted to be alternatively connected to provide com-- munication between the inlet and a pumping space and between the outlet and said pumping space, and adjustable valve means interposed between the outlet port and passageways extending from the pumping space to the outlet port, whereby a predetermined amount oi the output may be diverted from the output to effect a predetermined measured discharge or said pump, said valve means being also adapted to control the cut-off of fluid which is diverted from said, discharge port,

7. In a reciprocating pump, the combination of a pump housing provided with a pump chamber defined in part by a pair of opposed parallel plane surfaces, said housing being provided with a hear-- ing for a shaft, said shaft having an eccentric trunnion projecting into said chamber, a trunnion block having a bearing for receiving said trunnion and of a thickness adapted to be slidably received between said parallel walls, said trunnion being moved in a predetermined orbit by said trunnion, a piston block having an aperture provided with opposed plane surfaces for slidably engaging said trunnion block, said piston blocii: being of a thick,- ness having a sliding fit between the opposed surfaces of said chamber, and said piston block being 'reciprocated in said chamber by said trunnion block, a pair of valve members, one mounted on. each side of said piston, block. in said chamber, said valve members being movabiy mounted ior movement in the same direction as said piston provided with inlet and outlet ports and with passages and ports com municating with the space between the end of said housing and one end of said piston block, whereby the rotation of said shaft reciprocating said piston block automatically opens valves to the inlet port as said space increases in volume and closes said ports and opens other ports leading to the outlet port from said space when the piston bloci: moves in the opposite direction, the said valves and blocks and housing being provided with ports reciprocating type, the

and passages for the utilization of space at each end of said piston block in said housing as a double-acting pump.

8. In a reciprocating pump, the combination of a pump housing provided with a pump chamber defined in part by a pair of opposed parallel plane surfaces, said housing being provided with a bearing for a shaft, said-shaft having an eccentric surfaces of said chamber, and said piston block being reciprocated in said chamber by said trunnion block, a pair of valve members, one mounted on each side of said piston block in said chamber, said valve members being movably mounted for movement in the same direction as said piston block, said housing being provided with inlet and outlet ports and with passages and ports communicating with the space between the end of said' housing and one end of said piston block, whereby the rotation of said shaft reciprocating said piston block automatically opens valves tov the inlet port as said space increases in volume and closes said ports and opens other ports leading to the outlet port from said space when the piston block moves in the opposite direction, the said valves and blocks and housing being provided with ports and passages for the utilization of space at each end of said piston block in said housing as a double-acting pump, the said valves having ports and having transfer passages so arranged that the longitudinal movement of said valves effects a cut-off of intake and delivery of fluid pumped by said piston block to adjust the variable delivery of said pump.

9. In a fluid motor device, the combination of a housing having a piston chamber, a piston member mounted in said chamber for reciprocation, said chamber having inlet and outlet ports, and said piston having inlet and outlet conduits provided with piston ports communicating with a cavity therein forming a valve chamber for a reciprocating valve member, a valve member in said valve chamber having conduits and cut-off surfaces for controlling said piston ports, a shaft rotatably mounted on said device, and operative mechanical connections between said shaft and one of said members, whereby the shaft rotates as both members reciprocate.

10. In a fluid motor device, the combination of a housing having a piston chamber, -a piston member mounted in said chamber for reciprocation, said chamber having inlet and outlet ports, and said piston having inlet and outlet conduits provided with piston ports communicating with a cavity therein forming a valve chamber for a reciprocating valve member, a valve member in said valve chamber having conduits and cut-off surfaces for controlling said piston ports, a shaft rotatably mounted on said device, and operative mechanical connections hetweensaid shaft and one of said members, whereby the shaft rotates as both members reciprocate, and by-pass valve means arranged and constructed with conduits and cut-offsurfaces interposed between said piston conduits and said inlet and outlet ports, said valve means being selectively movable to vary gradually the 12 volume of fluid flow through said device by diverting fluid from the inlet and outlet ports to the other end oi the piston chamber from the end being used. i

11. In a fluid motor device, the combination of a housing having a piston chamber, a piston member mounted in said chamber for reciprocation, said chamber having inlet and outlet ports, and said piston having inlet and outlet conduits provided with piston ports communicating with a cavity therein forming a valve chamber for a reciprocating ivalve member, a

' valve member in said valve chamber having con duits and cut-oil" surfaces for controlling said r piston ports, a shaft rotatably mounted on said device, and operative mechanical connections between said shaftand one of said members, whereby the shaft rotates as both members reciprocate, said mechanical connections being between said shaft and valve member to cause said valve memher to reciprocate while moving in a circular path.

12. In a fluid motor device, the combination of a housing having a piston chamber, a piston member mounted in said chamber for recipro cation, said chamber having inlet and outlet ports, and said piston having inlet and outlet conduits provided with piston ports communieating with a cavity therein forming a valve chamber for a reciprocating valve member, a valve member in said valve chamber having conduits and cut-off surfaces for controlling said piston ports, a shaft rotatably mounted on said device, and operative mechanical connections between said shaft and one of said members, whereby the shaft rotates as both members reciprocate, said piston member and its chamber having plane rectangular sides engaging each other.

13. In a fluid motor device, the combination,

of a housing having a piston chamber, a piston member mounted in said chamber for reciprocation, said chamber having inlet and outlet ports, and "said piston having inlet and outlet conduits provided with piston ports communicating with a cavity, therein forming a valve chamber for a reciprocating valve member, a .valve member in said valve chamber having conduits and cut-off surfaces for controlling said piston ports, a shaft rotatably mounted on said device, and operative mechanical connections between said shaft and one of said members, whereby the shaft rotates as both members reciprocate, said piston member and its chamber having plane rectangular sides engaging each other, said valve member and its cavity in said piston having plane rectangular sides engaging each other, and said piston and valve member reciprocating in directions extending transversely to each other.

14. In a fluid motor device, the combination of a housing having a piston chamber, a piston member mounted in said chamber for reciprocation, said chamber having inlet and outlet ports, and said piston having inlet and outlet conduits provided with piston ports communicating with a cavity therein forming a valve chamber for a reciprocating valve member, a valve membar in said valve chamber having conduits and cut-off surfaces for controlling said piston ports,

a shaft rotatably mounted on said device, and operative mechanical connections between said shaft and one of said members, wherebythe shaft rotates as both members reciprocate, and by-pass valve means arranged and constructed with conduits and cut-off surfaces interposed between said piston conduits and said inlet and outlet ports, said valve means being selectively movable to vary gradually the volume of fluid flow through said device by diverting fluid from the inlet and outlet ports to the other end of the piston chamber from the end being used, and said mechanical connections being between said shaft and valve member to cause said valve member to reciprocate While moving in a circular path.

15. In a fluid motor device, the combination of a housing having a piston chamber, a. piston member mounted in said chamber for reciprocation, said chamber having inlet and outlet ports, and said piston having inlet and outlet conduits provided with piston ports communicating with a cavity therein forming a valve chamber for a reciprocating valve member, a valve member in said valve chamber having conduits and cut-off surfaces for controlling said piston ports, a shaft rotatably mounted on said device, and operative mechanical connections between said shaft and one of said members, whereby the shaft rotates as both members reciprocate, and by-pass valve 14 means arranged and constructed with conduits and cut-oii surfaces ton conduits and said inlet and outlet ports, said valve means being selectively movable to vary gradually the volume of fluid flow through said device by diverting fluid from the inlet and outlet ports to the other end of the piston chamber from the end being used, and said piston member and its chamber having plane rectangular sides engaging each other.

DAVID J. MUNROE. JOHN C. MCALVAY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS interposed between said pis- 

